Hose end coupling



May 9, 1967 Filed Oct. 22, 1965 K 32@ 25a 32.6 ,25 J2 I R. H. CULLEN ETAL HOSE END COUPLING 4 Sheets-Sheet l May 9, 1967 Filed Oct. 22, 1965 R.H. CULLEN ET'AL HOSE END COUPLING 4 Sheets-Sheet P /ITTORNEYS May 9,1967 R. H. CULLEN ETAL HOSE END COUPLING 4 Smets-sheet 5 Filed Oct. 22,1965 x MQ Foy H. Caf //@/7 @MY NN TTORNE YS May 9, 1967 R. H. CULLENET'AL HOSE END COUPLING 4 Sheets-Sheet 4 Char/95 .ff/Hoff 5 d m W m m Rm n ,A 4 u w fa W United States Patent O 3,318,620 HOSE END COUPLING RoyH. Cullen, Charles H. Elliott, Leslie D. Richards, Jimmie R. Aker, andWilliam E. Burke, Houston, Tex., assignors to Roy H. Cullen, Houston,Tex.

Filed Oct. 22, 1965, Ser. No. 501,031 6 Claims. (Cl. 285-149) ABSTRACT FTHE DISCLOSURE An end coupling for a exible pipe wherein at least onelayer of helically wrapped armor wires is held over a tapered couplingsurface by substantially circularly wrapped wire bonded together to forma solid ring.

In United States Patent No. 3,004,779 a wrapped pressure hose isdisclosed which is suitable for use as a flexible pipe in drilling wellsand similar operations. Such hose or flexible pipe has outer helicallywound wires or armoring thereon to protect the exible fluid conductorand to provide end pull strength and torque resistance. The wirewrapping or armoring has been held in place at the ends of each sectionof the hose or xible pipe with swage rings, the installation of whichrequires relatively expensive swaging equipment as well as precisemachining tolerances with respect to the swage rings,

An object of this invention is to provide a new and improved endcoupling whichhas all of the advantages of the coupling disclosed insaid Patent No. 3,004,779, and in addition thereto, has comparable orgreater strength without requiring the relatively expensive swagingequipment needed for manufacturing the end coupling of said Patent No.3,004,779.

Another object of this invention is to provide a new and improved endcoupling for a flexible pipe or hose having a plurality of helicallywound layers of armor wire, and method of making same, wherein the endsof the armor wire are secured on `an end coupling body by circularlydisposed holding wire which has a bonding agent such as an epoxy resintherewith for unitizing the holding wire.

The preferred embodiment of this invention will be described hereinaftertogether with other features thereof, and additional objects will becomeevident from such description.

The invention will be more readily understood from a reading of thefollowing specification and by reference to the accompanying drawingsforming a part thereof, wherein an example of the invention is shown andwhere- 1n:

FIG. l is a View, partly in elevation, and partly in section,illustrating the preferred form of the end coupling of this invention;

FIG. 2 is a quarter section taken on line 2 2 of FIG. 1 to illustratedetails with respect to the embodiment shown in FIG. l;

FIG. 3 is a quarte-r section taken on line 3 3 of FIG. 1 to illustratefurther details of the present invention;

FIG. 4 is a sectional View of a portion of the end coupling of thepresent invention illustrating an intermediate step in the method ofmanufacture of such coupling;

FIG. 5 is a view similar `to FIG. 4 but illustrating another step in themanufacture of the end coupling of this invention;

FIG, 6 is an elevation, partly in section, of a modified lform of theend coupling of this invention;

FIG. 7 is a quarter section taken on line 7 7 of FIG. 6;

FIG. 8 is a quarter section taken on line 8 8 of FIG. 6;

ICC

FIG, 9 is an elevation, partly in section, of a portion of the endcoupling of FIG. 6, with certain modifications;

FIG. 10 is a quarter section taken on line 10-10 of FIG. 9;

FIG. l1 is an'elevation, partly in section, illustrating still a furthermodification of the end coupling of this invention; `and FIG. 12 is avertical quarter section illustrating still another modification of theend coupling of this invention.

In the drawings, the letter F designates generally a flexible pipe orhose which is particularly suitable for supporting fluid-driven drillbits (not shown). At the end of each section of the exible pipe or hoseF, a coupling C is provided for connecting .the lengths or sections ofthe flexible pipe F together to form a continuous support or hose whichis adapted to be lowered into a well bore.

As illustrated in the drawings, the exible pipe or hose F includes aninner tube or fluid conductor 10 which is formed of rubber or anysimilar elastic resilient material and which serves as the main conduitthrough which the fluid ows during the use of the exible pipe or hose F.In order to provide for burst strength, the inner tube or flow conductor10 is surrounded by a two-ply wire braid which includes the wire braidlayers 12 and 14 which are of conventional construction. A coil spring15 surrounds the wire braid layer 14, and such spring 15 is formed ofmetal and is wound in a right-hand direction, with an elastomer filler16 between the layers making up the coil 15. Although the coil 15 ispreferably made of a resilient substantially rigid metal, it can beformed of other material so long as the material provides burst strengthand serves to prevent crushing or collapsing of the coil 15 when theflexible pipe or hose F is gripped by grippers in an `apparatus such asillustrated in United States Patent No. 2,892,535.

The coil spring 15 is surrounded by a plurality of helically wound wires19 which extend in a left-hand direction and which are providedprimarily for end pull strength. Such wires 19 are preferably wound atan angle of about 30 with respect to the vertical axis or longitudinalaxis of the flexible pipe or hose F. A second outer layer of wires 20surrounds the first outer layer of wires 19, and such wires 20preferably extend at an angle of about 30 with respect to the verticalor longitudinal axis of t-he hose F `but in a right-hand direction sothat they extend in an opposite direction from the wires 19. The wires20 provide for end pull strength, but they also provide for torqueresistance. The wires 19 and 20 are referred to herein as armor Wiressince they serve to also protect the internal portions of the flexiblepipe or hose F during use. Preferably, the outer layer of armor wires 20serves as the outer covering for the ilexible pipe or hose F, but anouter covering of rubber or similar resilient material (not shown) couldbe included over the armor wires 20 if so desired.

As seen in FIG. l, the coupling C includes a nipple 25 and a bodysection 26 which are threaded together at mating threads 2.7 to form 'aunitary assembly. The central bores 25a and 26a of -the memb-ers 25 and26, respectively, are in communication with the bore or interior 10a ofthe inner tube or fluid conductor 10,

The inner conductor 10 and the wire braid layers 12 and 14 `are clampedon the nipple 25 by a :clamping ring 32 which has buttress teeth 32aformed on the inner surface thereof for engagement with the outer layer14. The nippie 25 preferably has similar -buttress teeth 25b formed onits external surface and which engage the inner surface of the end ofthe fluid conductor 10 so as to confine the ends of the conductor 10 andthe wire 3 braid layers 12 and 14 between the buttress teeth 25b and32a. An inwardly extending annular flange 32b Von' the clamping ring 32fits into a circumferential groove C formed on the external surface ofthe nipple 25 to thereby retain the ring 32 against longitudinalmovement relative to the nipple 25. Ilfhe ring 32 can be of anyconventional type which is adapted to =be compressed for applying aclamping action to the layers 10, 12, and 14; but preferably the ring 32is a solid ring which is formed of metal or other material which retainsitself in a compressed condition yand is -applied yby swaging prior tothe disposition of the armor layers 19 'and 20 thereon in manufacture.

As will be explained more in detail in connection with the descriptionof the method or yprocess for the manufacture of the end coupling C ofthis invention, the ends of the armor wires 19 which are designated 19aare disposed on, a downwardly and outwardly tapered annular surface 26bwhich preferably has a layer of zinc or other embedding material 33formed thereon. The ends 19a of the armor wires 19 are held in positionon the tapered surface 26b by an initial retaining band or set of wires35 and by wire 36 which is circumferentially or circularly wound aroundthe ends 19a. As will be explained more in detail, a viscous liquid orsemisolid resin, such as epoxy resin, is applied during the process ofmanufacture so as to fill the spaces between the ends of the wires 19aand so as to coat and unify the wires 36. The external diameter 36a ofthe wire 36 conforms to the internal diameter of the outer layer ofarmor wires 20 as best seen in FIG. 1. Y

The ends 20a of the armor wires 20 are disposed on a surface 26C whichis similar to surface 26b and is likewise tapered downwardly andoutwardly with respect to the longitudinal axis ofthe flexible pipe orhose F. Preferably, a layer of zinc or other embedding material 38is'disposed between the ends of the wires 20a and the surface 26C forIproviding torque resistance, as will be explained more in detailhereinafter. The ends 20a are held in position in the same manner as theends 19a, preferably by a retaining band 40 and Wire 41 which iscircularly or Vcircumferentially wound around the ends 20a in the samemanner as the wires 36.

VThe final external surface of the wires 41 with the epoxy resin orsimilar coating therewith is preferably of substantially the samediameter as the external surface of the armor wires 20. The end couplingC has a radial ange 42 with an external surface'42a which conformsgenerally with, but is preferably slightly larger in diameter than, theexternal diameter of the wire 41 and the armor wires 20. Threads 43 areformed on the body 26 of the coupling C for connection with a femaleconnector or other suitable connecting means to join several of the hosesections together to form a continuous exible pipe for various depths indrilling operations. Internal threads 44 are also provided for themounting of suitable internal equipment which may be desired in thecourse of manufacture of the flexible pipe F or in connection with theuse of the pipe P in a well or other locathis invention for forming thefinal end coupling C of FIGS. 1-3.

The armor wires 20 are wrapped in a helical direction as best seen inFIG. 1 by any convenient Vor suitable armoring equipment. The ends 20aof the wires 20 are cut off so as to be of a proper length to iit on theexternal' tapered surface 26e so as to hold the ends 20aV while layingthem on the surface 26C. Thereafter, the ends 20:1 are then pressedradially inwardly by any suitable dies or rollers to force the ends 20ainto the embedding layer 38 formed of zinc or other equivalent material.During such radial force on the ends 20a, the ends 20a are alsostraightened so as to lay substantially axially or longitudinally withrespect to the longitudinal axis of the flexible pipe F. The embeddingof the wires 20a in the embedding layer 38 disposes such wires in axialorlongitudinal grooves to prevent a skidding or twisting of the wireswhen torque forces are created due to the action between the two armorlayers 19 and 20 when an end pull is applied to the exible pipe F.Instead of the zinc or other embedding layer 38, the surface 26C may bepreformed with longitudinally extending grooves to receive the ends 20aof the armor wires 20 of the same torque resistance provided by theembedding layer 38.

With the ends 20a of the armor wires 20 thus bent to conform with thetapered surface 26C, they become bunched as illustrated in FIG. 2 of thedrawing, and therefore such wires 20a are initially clamped or held attheir extreme outer ends by any suitable type of ring such as the wire40 which is relatively heavy wire Wrapped around such extreme ends ofthe armor wires 20. Instead of the wire 40, a split lock ring or otherclamping device may be employed, and such wire 40 or other clamping ringmay be removed after the ends 20a are firmly secured with the retainingwire 41, as will be more evident hereinafter. Normally, however, theretaining wire or band 40 is left in its clamping position asillustrated in FIG. 4. The voids between the ends 20a of the armor Wires20 as best seen'in FIG. 2 may be filled with an epoxy resin or otherlsuitable bonding agent,

which may thereby form a relatively smooth externalV surface 45 (FIG. 2)over the armor Wire ends 20a. In some cases, the embedding layer 38 mayitself form such external smooth surface 45 and may also be the materialfilling the voids between the overlapping and bunched ends 20a.

In any event, after the ends 20a of the armor wires 20 are laid in theposition illustrated in FIGS. 4 and 5, the relatively fine high tensilestrength Yholding or retaining Wire 41 is wrapped circularly orcircumferentially around the ends 20a to fill the space externally ofthe ends 20a and to provide a smooth external diameter which issubstantially the same as therexternal diameter of the armor wires 20and slightly smaller in diameter than the ange 42 (see FIG. 1)?. Atintervals throughout the wrapping process with the wires 41, a bondingagent or coating material such as the epoxy resin referred to above iscoated on the wires 41 to firmly unitize such wires and hold them intheir desired position. The epoxy resin is applied as a liquid orsemiviscous material as is wellV known, and thereafter such materialhardens Vto unite all of the wire 41 into a unitary holding element inthe form illustrated in FIGS. 1 and 2.

As schematically shown in FIG. 5, the wire 41 is fed from a spool 41a ofany conventional or suitable construction; and such wire 41 is appliedunder tension to obtain the maximum retaining force on the ends 20a ofthe armor wire 20. After the wire 41 has lled'the space together withthe epoxy resin or other bonding agent so as to provide the Vrelativelysmooth external surface indicated in FIG. 1 of the drawings, the Wire 41is severed from the spool 41a and the resin is allowed to Vharden.Lk

After the resin'has become set to a hardened condition, the clamp isremoved and the end coupling C is complete.

.It will be appreciated that the above procedure is applicable to thesecuring of the ends of the armor wires 'threads 27 or other suitablemeans.

19 with the wire 36 and that the application of the wire 36 is generallycompleted before the armor Wires 20 are applied.

In FIGS. 6-8, a modified exible pipe or hose F-l is illustrated whereinthe armor wire layers 19 and 20 are mountedA on a modied body section126 in a manner to be explained. The body section 126 is connected tothe nipple 25 in the same manner as the body section 26 is connected tothe nipple 25 in FIG. 1, namely, with The bore 126:1 of the body section126 is preferably in longitudinal alignment with the bore 25a of thenipple 25. The nipple 25 is connected to the hose 10 in the same manneras described and illustrated heretofore in connection with FIG. 1. Likeparts in FIGS. 1 and 6 bear like numerals or other designations.

The body section 126 is provided with annular tapered surfaces 126b,126C, 126d, and 126e. With the form of the invention illustrated inFIGS. 6-8, the bunching of the ends of the wires from the armor layers19 and 20 such as is illustrated in FIG. 2 is eliminated. This isaccomplished by disposing only the alternate ends 19a on the firstsurface 126b while disposing the other alternate ends 19b of the wires19 on the next tapered surface 126C. Similarly, the alternate ends 20aof the wires 20 are disposed on the tapered surface 126d, and the otheralternate ends 2Gb of the wires 20 are disposed on the tapered surface126e. It is to be noted that each of the surfaces 126b, 126e, 126d, and126e are provided with substantially axially or longitudinally extendinggrooves 133 (FIG. 8) into which the alternate wires are adapted to bedisposed to assist in preventing :any release of the ends of the wiresupon a torque force being applied to the exible pipe or hose F-1. Thus,as best seen in FIG. 8, the ends 20b are disposed in the grooves 133which are preformed in the surface 126e. The same grooves 133 areprovided on each of the other surfaces, and the corresponding ends 19a,19b, and 20a are disposed in the same manner as illustrated for the Wireends 20b in FIG. 8.

The wire ends 20h are embedded in a layer of an epoxy resin of the sametype as the resin or adhesive 45 previously described in connection withFIGS. 1 and 2. Thus, in FIG. 7, the epoxy resin 45 is illustrated aslling the spaces between the ends of the wires 2Gb. The wires 41 whichare wrapped over the epoxy layer `45 and the wires 20b (FIG. 7) are alsoas described heretofore in connection with FIGS. 1, 2, and 5. Althoughthe retaining wires 40 of FIGS. 1, 2, 4, and 5 are not illustrated inFIGS. 6 and 7, it will be understood that they may be employed ifdesired. In some cases, however, they may be eliminated; and for thatreason, the modiiication of FIGS. 6 and 7 does not show such wires 40.

' The wires 19a and 26a are mounted and would appear in cross sectionthe same as the illustrations of FIGS. 7 and 8 if taken at theappropriate cross sectional cut line.

The method of attaching the ends 19a, 19b, 20a and 2Gb to the bodymember 126 may be basically as illustrated and described heretofore inconnection with FIGS. 15, it being understood that the ends 19a are thefirst to be secured, and then the ends 19h are secured thereafter thesame manner. have been secured, the layer of wires 20 is wrapped overthe layer of wires 19 and then the ends 20a are first secured andthereafter the ends 2011 are secured, all employing the methodheretofore described Iand the materials employed in connection withFIGS. 1-5.

FIG. 9 illustrates a further modification of the exible pipe or hose Fand it is designated F-2 in FIGS. 9 and 10. The exible pipe F-2 has abody portion or cylinder 226 which corresponds with the body section 26of FIG. 1, except that the flange 242 is modified, as will be explained,as compared to the ange 42 of FIG. 1. Also, the ends of the wires 19aand 26a are bent upwardly and outwardly as seen in FIG. 9. The layerwires 20 are When the ends 19a and 19h disposed on the inclined surface126e and the layer of wires 19a are disposed on the inclined surface126b. The ends 19a of the wires 19 may lbe wrapped with Wire 41 in thesame manner as described in connection with FIG. 1, and also the ends ofthe wires 20a may be wrapped with the wire 41 as described in connectionwith FIG. 1. However, it is to be noted that the flexible pipe F-2 hasan annular wedge shaped retaining ring 60 which has an external diametersubstantially equal to the diameter of the layer wires 20 prior to theirbending to conform with the surface 126C. A retaining sleeve of metal orthe like indicated at 62 is slipped over the wires 41 to .protect suchwires 41 in use. The sleeve 62 is held in place by a retaining sleeve 65which is formed with internal splines that coact with correspondingsplines 126d on the body section 126. A suitable nut indicated in dottedlines at 66 holds the slidable retaining sleeve 65 in position on thebody 226 as illustrated in FIG. 9.

In FIG. 1l, a further modified exible pipe F-3 is illustrated whereinthe structure is identical to that illustrated in FIG. 9, except thatthe retaining sleeve 365 is secured to the body 226 by key elements 365awhich are disposed in suitable keys 326d. Like parts in FIG. l1 whichcorrespond with those in FIGS. 9 and 10 bear like numerals so that itcan be seen that the structure of FIG. ll is basically the same as thatillustrated in FIGS. 9 and 10, except for the retaining sleeve 365.

FIG. l2 indi-Cates a further modified exible pipe 0r hose F-4 `which hasa sleeve 462 that is integral with a shoulder 46211 to limit themovement of the sleeve 462 inwardly. The sleeve 462 also has suitablesplines 462b which coact with the corresponding splines on the tubularbody section 426 so as to prevent relative rotation 'between the sleeve462 and the lbody section 426. The sleeve 462 is held in position by aretaining nut 66 indicated in dotted lines, or any other suitableretaining element.

Reference is now made to FIG. 6, wherein an angle X is illustrated withrespect to the surface 126e. With the present invention, when the wires41 are wrapped and bonded together with the epoxy resin in a mannerillustrated and described heretofore in connection with FIGS. l-5, andas employed in the other forms of the invention disclosed herein also,such wires 41 act as a solid ring and become a self-tightening ringunder certain conditions of construction. The self-tightening feature ofthe wires 41 occurs when the coefficient of friction between the solidlayer of wires 41 and the ends 19b is greater than the tangent of theangle X. Such construction causes the ring of wires 41 to ride with thewires 19 and the ends 19b thereof so as to wedge such ends 19b moretightly as end pull is exerted on the wires 19. Although therelationship between the ring of wires 41 and the wires 1912 has beendescribed specifically, it will be understood that the same conditionfor selftightening may be related to the other wires 19a, 20a and 20b inthe FIG. 6 form of the invention. Likewise, the same conditions willprevail with respect to the ring of wires 36 and the wire ends 19a inFIG. l and the ring of wires 41 and the wire ends 20a in FIG. l.

Stated differently, the product of the inward radial forces produced bythe application of the wires 41 on the wire ends 19b as viewed in FIG. 6plus the outward radial forces generated by pulling the ring of wires 41up the inclined surface provided for by 126C in FIG. 6, or combinationsof the foregoing radial forces, multiplied by the coefficient offriction between the armor wire ends 19b and the inclined surface 1260must be at least equal to the end pull load applied to the wires 19bbefore the stresses in the enclosing wire ring provided by the wires 41approach their elastic limit. Such relationship also exists with respectto the ends 19a, 20a and 20b in the various forms of the invention.

It should be understood that although certain figures illustrateparticular modifications or embodiments of the present invention, -suchmodications or embodiments may be combined in various ways to form-other embodiments within the scope of the present disclosure. Forexample, the wires 19a and 20a in FIG. 9 are shown as being curvedupwardly and outwardly, and 4such feature is also usable in FIGS..1 and6, and other versions of the present invention. Likewise, the retainingsleeve 62 of FIGS. 9, 1l and the retaining sleeve 462 of FIG. 12 may beused in either of the modifications of FIGS. 1 and 6, or othercombinations thereof. It should also be understood that although theform of the invention illustrated in FIGS. 1-3 includes the relativelysoft embedding layer 33, such layer 33 may be formed as preformedgrooves in the metal of the holding body section 26 in the same mannerasV illustrated in FIG. 6, and similarly, a soft embedding material maylbe disposed on the inclined surfaces 126b, 126C, 126d and 126e ratherthan providing the preformed grooves 133 as illustrated in FIGS. 6-8.

The foregoing disclosure and description of the invention isillustrative and explanatory thereof and various changes in the size,shape and materials, as well as in the details of the illustratedconstruction, may be made within the scope of the appended claimswithout departing from the spirit of the invention.

What is claimed is:

1. An end coupling for a exible pipe having a tubular uid conductor withat least one layer of armor wire thereon, comprising:

(a) an end coupling body having an inner bore in communication with thebore of the tubular fluid conductor,

(b) means connecting said end coupling body to the uid conductor,

(c) said end coupling body having an external annular surface which istapered downwardly and outwardly with respect to the tubular uidconductor and which is adapted to receive the ends of the layer of armorwires thereon,

(d) a plurality of helically wrapped armor wires for end pull strengthwhose maximum inside diameter is approximately equal to the maximumoutside diameter of the tapered surface,

(e) the ends of the armor Wires being disposed so as to conformgenerally to the taper of said external surface,

(f) holding wire wrapped substantially cirrcularly about the ends of thearmor wires which are dis- Y posed over the tapered section to hold thearmor wires against the tapered surface, and

(g) bonding material within the spaces between the (a) the outer surfaceof the wrapped holding wire is substantially cylindrical and ofsubstantially the same external diameter as the external diameter of thearmor wires at the maximum diameter of the tapered surface.

3. The structure of claim 1, wherein: Y

(a) said bonding material is an epoxy resin which hardens to unitize theholding wires.

4. The structure of claim 1, wherein:

(a) the ends of said armor wires which are disposed on said taperedsection are positioned substantially axially of the end coupling body,and

(b) said ends of the armor wires are bunched at the smallest diameterportion of the tapered section.v

5. The structure of claim 1, wherein:

(a) said external surface has grooves in which the armor wires aredisposed for torque resistance.

6. The structure of claim 1, wherein: n

(a) an embedding layer of relatively softer metal as compared to themetal of the coupling body is provided on said tapered surface forembedding the armor wires therein when held by said holding wire.

References Cited by the Examiner UNITED STATES PATENTS 986,081 3/1911PatterSOn 285-254 2,234,350 3/1941 Muller 285-149 2,237,490 4/ 1941KnOWland 285-149 2,878,038 3/1959 Noland 285-432 X 2,940,778 6/ 1960Kaiser 2875-149 X 3,004,779 10/1961 Cullen et al. 285-149 FOREIGNPATENTS 648,562 1/ 1951 Great Britain.

CARL W. TOMLIN, Primary Examiner.

THOMAS F. CALLAGHAN, Examiner.

1. AN END COUPLING FOR A FLEXIBLE PIPE HAVING A TUBULAR FLUID CONDUCTORWITH AT LEAST ONE LAYER OF ARMOR WIRE THEREON, COMPRISING: (A) AN ENDCOUPLING BODY HAVING AN INNER BORE IN COMMUNICATION WITH THE BORE OF THETUBULAR FLUID CONDUCTOR, (B) MEANS CONNECTING SAID END COUPLING BODY TOTHE FLUID CONDUCTOR, (C) SAID END COUPLING BODY HAVING AN EXTERNALANNULAR SURFACE WHICH IS TAPERED DOWNWARDLY AND OUTWARDLY WITH RESPECTTO THE TUBULAR FLUID CONDUCTOR AND WHICH IS ADAPTED TO RECEIVE THE ENDSOF THE LAYER OF ARMOR WIRES THEREON, (D) A PLURALITY OF HELICALLYWRAPPED ARMOR WIRES FOR END PULL STRENGTH WHOSE MAXIMUM INSIDE DIAMETERIS APPROXIMATELY EQUAL TO THE MAXIMUM OUTSIDE DIAMETER OF THE TAPEREDSURFACE, (E) THE ENDS OF THE ARMOR WIRES BEING DISPOSED SO AS TO CONFORMGENERALLY TO THE TAPER OF SAID EXTERNAL SURFACE, (F) HOLDING WIREWRAPPED SUBSTANTIALLY CIRCULARLY ABOUT THE ENDS OF THE ARMOR WIRES WHICHARE DISPOSED OVER THE TAPERED SECTION TO HOLD THE ARMOR WIRES AGAINSTTHE TAPERED SURFACE, AND (G) BONDING MATERIAL WITHIN THE SPACES BETWEENTHE HOLDING WIRE AT THE TAPERED SECTION TO UNITIZE THE HOLDING WIRE INTOA SOLID RING HAVING AN INNER INCLINED SURFACE SO THAT WHEN THECOEFFICIENT OF FRICTION BETWEEN THE UNITIZED SOLID RING AND THE ENDS OFTHE ARMOR WIRE IS GREATER THAN THE TANGENT OF THE ANGLE OF THE TAPEREDSURFACE WITH RESPECT TO AXIS OF THE COUPLING BODY SELF-TIGHTENING OF THESOLID RING WILL OCCUR IF THE ARMOR WIRES START TO MOVE UP THE TAPEREDSURFACE.